2021 Chevrolet Tahoe: engine knocking or ticking

Filed Aug 22, 2026 · Engine · MO

Engine failure of the 6.2L L87. Was 12 hours from home with my family on vacation in Colorado cruising up a 4 lane mountain highway about 700 yards from entering [XXX] thru the mountain and the engine started screaming and knocking. Thank the lord there was a way I could quickly steer my vehicle and family off the 65 mph hwy. Engine had recently passed the recall inspection test. “3,000ish miles ago” dealership confirmed engine failure and it’s sitting in cooorado waiting for a replacement engine. I believe this will be the 3rd engine now in my car. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Jun 30, 2026 · Engine, Fuel system · IN

The engine's Dynamic Fuel Management (DFM) lifter failed and damaged the camshaft at around 70,700 miles. The broken components are available for inspection upon request. This failure put occupants at risk because the vehicle suddenly lost power, began shaking violently, and could not accelerate safely in traffic. This unexpected loss of propulsion created an immediate collision hazard. The problem was officially diagnosed and confirmed by a repair service center. It has not been inspected by police or insurance representatives. There were no advance warning signs. At the exact moment of the failure, the check engine light started flashing, the car began shaking heavily, and the engine made a loud knocking sound.

Filed Apr 13, 2026 · Engine, Suspension · KY

Suspension system failed- had to replaced, Car difficult to control when operating. Repaired by dealer- Country Chevrolet, Benton KY- owner paid for repair. [XXX] Engine failure- knocking and difficult to drive on returning trip from Louisville KY to Benton, KY. Taken to dealer on 4.6.2026 - made it without being towed- extremely slow- traffic hazard- Tahoe has lots of road miles- always repaired and serviced by dealer. There were no warning lights, symbols or indicators that there was a problem. Dealer still determining the extent of the damage. [XXX] Benton KY INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Apr 12, 2026 · Driver assistance, Engine · CA

The component at issue is the engine, which suffered a sudden and catastrophic failure due to unknown causes. At no time prior to this incident were there any warnings, symptoms, or indications of an underlying mechanical defect that would have allowed for preventative action. While operating the vehicle on the highway with my family present, multiple warning indicators activated simultaneously, including a blinking check engine light, traction control light, ESC warning, and a forward collision warning. Immediately thereafter, the vehicle experienced a rapid and significant loss of power accompanied by a loud and persistent engine knocking noise, rendering the vehicle unsafe to operate and placing the occupants at risk. It is important to emphasize that traction control and ESC systems are not causally related to an engine misfire condition, further supporting that this event was abrupt and not part of a progressive or diagnosable issue. A diagnostic scan performed at that time identified a misfire in cylinder 1. Upon delivery of the vehicle to the dealership for inspection, it was determined that the engine had suffered complete internal failure and was deemed “blown.” This finding confirms the occurrence of a catastrophic mechanical breakdown. Based on the sudden onset, absence of prior warning, and severity of the failure, there is no reasonable basis to attribute this condition to normal wear and tear, operator misuse, or neglect. Rather, the facts support the conclusion that this was the result of a latent defect or internal mechanical failure beyond the operator’s control. Accordingly, this matter should be addressed under applicable warranty coverage or consumer protection standards.

Filed Apr 10, 2026 · Electrical, Engine · LA

During highway driving, alert on dashboard stated “electrical system failing enter idle mode”. Tahoe slowed down and then engine began knocking right as it shut off resulting in needing to coast to the shoulder of the highway safely since engine was off. Towed to dealership and then they came back saying needed a new battery, new alternator belt, pulley and water compartment. After those installed, additional call was made indicating the engine needed a full replacement as it keeps overheating despite no sensor alerts and codes are being tripped. Here we are asked to pay 16K for new engine install and unable to fix.

Filed Mar 11, 2026 · Engine · 51,000 miles · CA

The contact owns a 2021 Chevrolet Tahoe. The contact stated that the engine was consuming an excessive amount of oil, and there was an abnormal knocking sound coming from the engine. Additionally, the vehicle hesitated and failed to accelerate as needed, with blue smoke coming from the exhaust pipes. The check engine warning light was intermittently illuminated. The vehicle was taken to the dealer, who determined that there were metal shavings in the engine oil and that the engine needed to be replaced. The vehicle was not repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 51,000.

Filed Mar 7, 2026 · Driver assistance, Electrical · AR

My truck was driving perfect and I went to pull into a parking lot in Arkansas where I live in long story short it started acting funny trying to idle out and then I heard a knocking noise. It happened twice. Then my service ESV light come on next my motor light come on then my auto for a collision system failure light come on. It’s on the dash anyway my vehicle is not running around. It has hardly no power and I smell something under the hood from time to time burning it’s kinda like an electrical smell. I’m not sure. I’m not a mechanic. I’m a [XXX]. I’m a [XXX]!!! but I have to have a way back back-and-forth to work and I cannot drive this vehicle. I have been driving it to work and just straight to home and that’s only like a mile from the shop but I need a replacement vehicle I need to sell mine at wholesale value as you guys said you would that would be greatly appreciated. God bless you guys. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Mar 6, 2026 · Engine · 72,000 miles · KY

The contact owns a 2021 Chevrolet Tahoe. The contact stated that while driving at various speeds, the Forward Collision Avoidance message was intermittently displayed. The vehicle was taken to a dealer, where a computer module was replaced. While driving at various speeds, there was an intermittent knocking sound coming from the engine, with the check engine warning light illuminated. While driving at an undisclosed speed, the knocking sound became constant. The vehicle was driven to the dealer, and upon inspection, the mechanic discovered a bent engine rod inside the engine. The vehicle was diagnosed with engine failure, and the contact was provided an estimate for the repair. Upon investigation, the contact discovered the failure was associated with the federal safety agency Campaign Number: 25V274000 (Engine and Engine Cooling). The manufacturer was initially notified of the failure through the dealer, and the contact was later informed that the manufacturer agreed to cover half the cost of an engine replacement. Upon calling the manufacturer directly, the contact was referred to the federal safety agency Hotline to report the failure. The vehicle was not repaired and remained with the dealer. The failure mileage was approximately 72,000.

Filed Feb 15, 2026 · Engine · CO

While driving home late at night, the vehicle experienced a sudden mechanical failure in the engine. I was traveling approximately 2 miles per hour while slowing to stop at a stop sign when there was a loud “clunk,” followed by an abrupt stop of the vehicle. Immediately after this occurred, multiple dashboard warning lights illuminated, and a knocking sound began coming from the engine. The vehicle is currently not operating normally and is available for inspection upon request. This incident occurred late at night while I was driving with my two young children in the vehicle. The sudden and unexpected stop put us at risk of being rear-ended or stranded in an unsafe location. The loss of normal vehicle operation created a dangerous situation, especially given the time of night, location, and the presence of my children. There were no warning lights, messages, or noticeable symptoms prior to the incident. All warning lights illuminated only after the loud clunk and abrupt stop occurred. The knocking sound from the engine began immediately following the failure. I now am in a rental car that costs $700 a week that my insurance doesn’t cover.

Filed Feb 6, 2026 · Transmission · NE

2021 tahoe with 3.0L diesel engine and 139k miles recently began overheating when on interstate but temp would jump up quickly then quickly back down. Reduced acceleration mode is triggered and AC is turned off automatically. Diagnostic report shows coolant control valve error code and it was explained to me that valve is sticking then as engine pressure rises, it knocks it loose again explaining the quickly jumps and dips in temp. Fan runs constantly from moment it is started too. When looking for the part online to get an idea of repair cost, there was a bulletin about this being a known issue in the 2021 tahoes with the diesel engines and bulletin states GM extended special coverage for 15yrs/150k miles. When I called dealer to schedule service, I was told this bulletin doesnt come up under my vin number despite it having the same issues, error codes, year, make, model, and engine.

Filed Feb 1, 2026 · Engine · CT

The vehicle stalled while driving down the road and started making a loud ticking noise, the engine light went on. It was brough to the dealership where they did an engine rebuild. They replaced 16 lifters and camshaft, a pulley belt and gaskets. The vehicle was picked up, however, a month later the oil low add oil light came on and the oil tank was more than 2.5 quarts low indicating extreme burning of oil. The vehicle is shuttering on acceleration of low RPMs. Brought it back to the dealership and awaiting further instruction. It caused a major safety concern because it has the potential to stall due to a motor defect on a major highway, putting my family and possibly others at risk of harm or death.

Filed Jan 31, 2026 · Driver assistance, Engine · PA

Lost Power. Engine went into a limp mode. Engine starting knocking loudly and service esc came up on dash along with check engine light. Took it to the dealer and they said a lifter spun and damaged the camshaft. Dealer says it’s not covered by recall. Vehicle has been in Chevy dealer garage for 2 weeks and no repair yet.